1. Technical Field
The present invention relates generally to processing document images, and more specifically relates to a system and method for measuring a skew of an image by analyzing the slope of printed information in the image.
2. Related Art
Handling and processing document images is becoming more and more important with the advancement of electronic commerce in environments such as banking. For example, under the “Check 21 Act,” which goes into law in October of 2004, banks will be allowed to exchange check images, without actually having to present the original check, for conducting transactions. An important challenge for handling such images includes measuring the image quality of the check. If for example, the check code line, which contains account information and the like, cannot be read, the image must be identified as being unacceptable. Given the high volume of checks that will be processed electronically, automated systems that efficiently measure image quality are required.
One important area of image quality involves document skew. The ability to accurately measure skew can help determine whether printed information can be accurately read in an automated fashion. Too much skew may indicate that the document is unacceptable and/or needs correction before the data can be read.
Known methods for measuring skew typically rely on use of the scanned document image edges to establish image skew. However, it is not unusual for images to be cropped such that the document edges have been removed. In these cases, skew measurements cannot be reliably obtained. Accordingly, a need exists for a system and method for measuring a skew angle of a black white document image.